Paste composition, green ceramic body, and methods for manufacturing ceramic structure

Abstract

A paste composition comprises inorganic particles; and a binder containing a copolymer made by copolymerizing a mixture. The mixture comprises a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h]; and a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l] lower than the first glass transition temperature Tg[h]. The total molar fraction of the first and second (meth) acrylic esters in the mixture is 80 mol % or more. The first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧50° C.

1 . A paste composition comprising:
 inorganic particles; and   a binder containing a copolymer made by copolymerizing a mixture, wherein
 the mixture comprises
 a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h]; and 
 a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l] lower than the first glass transition temperature Tg[h], 
 wherein the total molar fraction of the first and second (meth) acrylic esters in the mixture is 80 mol % or more, and 
 wherein the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧50° C. 
 
   
     
     
         2 . The paste composition according to  claim 1 , wherein the mixture further comprises a third (meth)acrylic ester having at least one polar functionality, selected from the group consisting of (meth)acrylic ester having hydroxyl group and (meth)acrylic ester having polyalkylene oxide chain. 
     
     
         3 . The paste composition according to  claim 1 , wherein the binder has a weight-average molecular weight in the range of 20,000 to 100,000. 
     
     
         4 . The paste composition according to  claim 1 , further comprising 0.1 to 10 parts by weight of nitrocellulose to 100 parts by weight of the binder. 
     
     
         5 . The paste composition according to  claim 1 , wherein 99 percent by weight of the binder is thermally decomposed in a nitrogen atmosphere at 500° C. 
     
     
         6 . The paste composition according to  claim 1 , wherein the inorganic particles comprises glass particles containing silica. 
     
     
         7 . The paste composition according to  claim 1 , wherein the inorganic particles comprises electroconductive material. 
     
     
         8 . The paste composition according to  claim 1 , wherein the inorganic particles comprises dielectric material. 
     
     
         9 . The paste composition according to  claim 1 , wherein the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationship Tg[h]−Tg[l]≦250° C. 
     
     
         10 . A green ceramic body comprising:
 a green ceramic base; and   a paste composition applied to the green ceramic base, the paste composition including inorganic particles, and a binder containing a copolymer made by copolymerizing a mixture, wherein the mixture comprises
 a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h], and 
 a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l] lower than the first glass transition temperature Tg[h], 
 wherein the total molar fraction of the first and the second (meth)acrylic esters in the mixture is 80 mol % or more, and 
 wherein the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧50. 
   
     
     
         11 . The green ceramic body according to  claim 10 , wherein the inorganic particles of the paste composition contains glass particles, and the green ceramic base contains glass particles having the same composition as the glass particles of the paste composition at least in the portion to which the paste composition is applied. 
     
     
         12 . A method for manufacturing a ceramic structure comprising:
 preparing a paste composition containing inorganic particles and a binder containing a copolymer made by copolymerizing a mixture comprising a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h] and a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l], wherein the total molar fraction of the first and the second (meth)acrylic esters in the mixture is 80 mol % or more and the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧50° C.;   forming a green ceramic body by applying the paste composition to a green ceramic base by printing; and   firing the green ceramic body.   
     
     
         13 . A method for manufacturing a ceramic structure comprising:
 applying a paste composition containing inorganic particles and a binder containing a copolymer made by copolymerizing a mixture comprising a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h], and a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l], wherein the total molar fraction of the first and the second (meth)acrylic esters in the mixture is 80 mol % or more and the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧50° C.;
 to a first ceramic green sheet by printing; 
   planarizing the surface of the paste layer by pressing the paste layer at a temperature 30±5° C. higher than the glass transition temperature of the binder so as to plastic-deform the paste layer.   
     
     
         14 . The method according to  claim 13 , wherein the paste layer has a thickness t after being planarized, and the thickness t and the thickness T of the first ceramic green sheet in contact with the paste layer satisfy the relationship: t≦0.7T. 
     
     
         15 . A paste composition comprising:
 inorganic particles; and   a binder containing a copolymer comprising   a first (meth)acrylic ester unit whose homopolymer has a first glass transition temperature Tg[h]; and   a second (meth)acrylic ester unit whose homopolymer has a second glass transition temperature Tg[l] lower than the first glass transition temperature Tg[h],   wherein the total molar fraction of the first and second (meth) acrylic esters in the mixture is 80 mol % or more, and   wherein the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧50° C.   
     
     
         16 . A method for manufacturing a ceramic structure comprising:
 Applying a paste composition containing inorganic particles and a binder, comprising a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h] and a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l], wherein the total molar fraction of the first and the second (meth)acrylic esters in the mixture is 80 mol % or more and the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationships Tg[h]≧100° C. and Tg[h]−Tg[l]≧5° C.;   to a green ceramic body by printing; and   firing the green ceramic body.   
     
     
         17 . A green ceramic body comprising:
 a green ceramic base having a paste composition thereon; the paste composition including inorganic particles, and a binder containing a copolymer comprising   a first (meth)acrylic ester whose homopolymer has a first glass transition temperature Tg[h], and   a second (meth)acrylic ester whose homopolymer has a second glass transition temperature Tg[l] lower than the first glass transition temperature Tg[h],   wherein the total molar fraction of the first and the second (meth)acrylic esters in the copolymer is 80 mol % or more, and   wherein the first and the second glass transition temperatures Tg[h] and Tg[L] satisfy the relationship Tg[h]≧100° C. and Tg[h]−Tg[l]≧50.   
     
     
         18 . The method according to  claim 13 , further comprising stacking a second ceramic green sheet on the first ceramic green sheet with the paste layer therebetween, pressing the stack plates to form an integrated ceramic green body, and firing the integrated ceramic green body.